๐ Glaucoma Treatment – Beta Blocker (BB) Review
Beta blockers (BB) are first-line glaucoma medications that lower intraocular pressure (IOP)
by inhibiting β2 receptors, thereby reducing aqueous humor production.
๐ Common BB Agents & IOP Reduction
DrugBrand NamesIOP Drop (mmHg)
| Levobunolol | Betagan | 4.51 |
| Timolol | Timoptic | 3.7 |
| Carteolol | Cartelol | 3.44 |
| Betaxolol | Betoptic | 2.24 |
โก Timolol is the standard comparator in trials
๐ Limitations of Timolol
NameExplanation
| Short-term escape | IOP lowers initially, rebounds within days |
| Long-term drift | Effect gradually fades after 3–12 months |
โ Dipivefrin was used to reset sensitivity but is no longer available in Korea
โ Adverse Effects
๐ Ocular Effects
- Dry eye
- Corneal anesthesia
- Ocular cicatricial pemphigoid (OCP)
๐ Systemic Effects
SystemReceptorEffects
| Cardiovascular | β1 | Bradycardia, arrhythmia, heart failure |
| Respiratory | β2 | Bronchospasm, asthma exacerbation |
| CNS | — | Depression, drowsiness, anxiety |
| Lipid Profile | — | ↓ HDL cholesterol |
โก Non-selective BBs (Timolol, Carteolol, etc.) affect both β1 & β2
โก Even Betaxolol (β1-selective) can cause mild respiratory side effects
โ Summary
- BBs work by reducing aqueous production via β2 blockade
- Timolol = most studied, but has escape/drift phenomena
- Systemic monitoring is essential, especially in heart/lung disease
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